RESUMO
Camellia confuse Craib 1914 is an industrially valuable oil crop from southern China for which little genetic information is available. Here, we found that its complete chloroplast genome is a circular sequence (156,905 bp) with a large single-copy region (LSC) of 67,724 bp, a small single copy region (SSC) of 18,400 bp, and two inverted repeats (IRs). In total, 130 genes were identified, including 86 protein-coding genes, 36 transfer RNAs, and 8 rRNA genes. Phylogenetic analysis showed that C. confusa is close to C. meiocarpa. These results provide valuable information for accelerating research on the evolution of camellias.
RESUMO
The flavonoids metabolic pathway plays central roles in floral coloration, in which anthocyanins and flavonols are derived from common precursors, dihydroflavonols. Flavonol synthase (FLS) catalyses dihydroflavonols into flavonols, which presents a key branch of anthocyanins biosynthesis. The yellow flower of Camellia nitidissima Chi. is a unique feature within the genus Camellia, which makes it a precious resource for breeding yellow camellia varieties. In this work, we characterized the secondary metabolites of pigments during floral development of C. nitidissima and revealed that accumulation of flavonols correlates with floral coloration. We first isolated CnFLS1 and showed that it is a FLS of C. nitidissima by gene family analysis. Second, expression analysis during floral development and different floral organs indicated that the expression level of CnFLS1 was regulated by developmental cues, which was in agreement with the accumulating pattern of flavonols. Furthermore, over-expression of CnFLS1 in Nicotiana tabacum altered floral colour into white or light yellow, and metabolic analysis showed significant increasing of flavonols and reducing of anthocyanins in transgenic plants. Our work suggested CnFLS1 plays critical roles in yellow colour pigmentation and is potentially a key point of genetic engineering toward colour modification in Camellia.